Quick disconnect coupling for coaxial fluid lines

ABSTRACT

A coaxial quick disconnect coupling for coaxial fluid lines including an external plug-and-socket combination having an internal plug and socket mounted coaxially therein. Preferably, the internal plug member is mounted within the external socket portion of the connector while the internal socket is mounted within the external plug portion. Valves incorporated in the internal plug and socket prevent flow of the fluid in the coaxial line when the assembly is disconnected.

CROSS REFERENCE TO RELATED APPLICATION

This is a continuation of copending application, Ser. No. 438,690, filedFeb. 1, 1974 now abandoned, which was a division of prior applicationSer. No. 222,890 filed Feb. 2, 1972, now U.S. Pat. No. 3,820,827.Accordingly, this application is also a division of such patent.

BACKGROUND OF THE INVENTION

Coaxial fluid lines have long been used in industry to deliver variousfluids from a source to a point of utilization. Oil and air, forexample, are quite commonly delivered in coaxial lines to power andlubricate air-driven tools, motors, and the like. Such systems generallyinclude coaxial fluid transmission lines connected from the tool to amanifold block, an injection lubricator, or the like, when the oil andair is introduced from separate sources. The lines are generallyprovided with threaded connector ends which are threadably received onthe tool and the manifold block. Replacement of the tool ordisconnection from the manifold block requires that at least one of thethreaded ends be removed by the use of a wrench or the like. In otherapplications, coaxial tubing utilized to deliver various fluids to anozzle or the like where it is mixed or misted for lubrication ofcutting tools or similar applications. In either event, it is verydesirable to have a coupling, and particularly a "quick-disconnect"coupling, for connecting and disconnecting the coaxial supply lines as aunit such that the tool, nozzle, or other item to which the individualfluids are delivered in the coaxial tubing may be readily removed orconnected; however, whereas quick-disconnect couplings have long been inuse for single fluid tubes, no suitable such device has heretofore beenavailable for coaxial pairs of tubes or lines.

SUMMARY OF THE INVENTION

The present invention, therefore, provides a coupling for coaxial fluidlines wherein connection and/or disconnection of a pair of coaxial linesmay be readily and instantly accomplished. The connector of the presentinvention comprises a first connector structure having an external orouter plug-and-socket portion adapted for mutual connection in serieswithin a first fluid supply line and locked in together by conventionalsocket-locking mechanism. A second, internal coaxial connectingstructure is centrally located within the first connecting structureand, in a preferred embodiment, includes an interior plug member mountedwithin the first or outer socket and an interior socket member mountedwithin the first or outer plug. Each plug and socket is in generalcoaxial alignment with the supporting components. Either or both of thefirst and second connecting structures may include check valves toprevent flow of the fluids when disconnected. The inner or second plugextends within the first socket and may be mounted for slight radial, orskewing and/or rotary movement therewithin, (any of which may be termed"angular movement") to facilitate automatic alignment of the componentparts as they are connected, and prevent tubing windup. Also, thearrangement of parts is such that when the coupling is connectedtogether, the inner plug and socket connect together and seal againstleakage before fluid can flow through the outer plug and socket, andthey do not disconnect until fluid pressure in the outer plug and socketis relieved, a feature which can be very important, especially in thelubrication of air tools.

Accordingly, it is a primary object of the present invention to providea coupling member for coaxial fluid lines.

It is another object of the invention to provide a quick disconnectcoupling member for coaxial fluid lines.

It is another object of the invention to provide a coaxial connectorunit adapted for use with coaxial fluid lines.

It is yet another object of the present invention to provide a coaxialconnector having valve means therein to automatically block the flow offluids as the connector portions are disconnected.

These and other important objects, advantages, and features of thepresent invention will become more apparent upon reading the followingspecification and with references to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described with reference to the accompanyingdrawings in which:

FIG. 1 is a perspective view of a coupling member incorporating thepresent invention;

FIG. 2 is a cross-sectional view of the coupling member shown in FIG. 1;

FIG. 3 is an enlarged, fragmentary cross-sectional view similar to FIG.2 illustrating the inner plug-and-socket in an engaged position, withparts of the outer connector eliminated for clarity;

FIG. 4 is an end view of the plug shown in FIG. 3;

FIG. 5 is a cross-sectional view similar to FIG. 3 but illustrating analternate check valve arrangement utilized in the plug portion of thecoaxial connector;

FIG. 6 is a cross-sectional view similar to FIG. 2 illustrating analternate coupling member incorporating the present invention;

FIG. 7 is a cross-sectional view illustrating a modified inner plugarrangement having a check valve therein for use with Venturi-typelubricators.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings and in particular to FIGS. 1 and 2, theconnector or coupling of the invention will be described in detail.Basically, the invention includes a connector assembly having a first orouter socket portion 10 and a first or outer plug portion 12. Positionedcoaxially within such first socket-and-plug portions is a second orinner plug 14 and a second or inner socket 16. Preferably, the second orinner plug is disposed within the first or outer socket, and the secondsocket within the first plug. The first or outer plug-and-socketcombination are basically of conventional construction, and include anelongated valve body 18 (FIG. 2) into which a socket receiver body 20 isthreadably fastened. A plurality of locking balls 22 are spaced inrecesses formed about the outer diameter of the socket receiver body 20for cooperative locking engagement within a peripheral groove or recess24 formed in the outer plug portion 12. A sleeve 26 is slidably mountedalong the length of the body 18 to move the balls 22 inwardly and intolocking engagement with the outer plug 12.

To allow the flow of a first fluid through the outer plug and socketportions of the coupling, both the valve body 18 and the receiver 20have a continuous communiating passageway 19 and 19a formed along theirlength (FIG. 2). A barrier member or wall 28 is formed in the passageway19 of the body 18 and a plurality of orifices 30 are provided on eitherside of the barrier. The orifices 30 extend radially outwardly on bothsides of the barrier. A sleeve valve 32 having a circumferential groove34 formed in its inner diameter is slidably mounted on the valve body.The sleeve valve 32 is shiftable between open and closed positions withrespect to the orifices 30 to control the flow of fluid through thebody. As illustrated in FIG. 2, the valve is in a closed position. Whenopen, the sleeve is shifted toward the right such that the orifices 30communicate with each other through the passageway formed by radialgroove 34, which then spans the barrier 28. A plurality of O-rings 36are suitably placed in grooves or slots about both the outer diameter ofthe body 18 and the outer diameter of the valve sleeve 32 to preventleakage of the fluid from about the valve sleeve and body. Sleeve biasspring 41 is provided to bias sleeve 26 along the valve body and socketinto a locked position when the plug 12 is inserted into the socketreceiver body 20. Coil spring 38 biases plug 12 outwardly when thesleeve 26 is moved to an unlocked position for ease of removal.

As will be known by those skilled in the art, that which has been thusfar described, with the exception of the briefly-mentioned second orinner plug and socket 14 and 16, is of conventional construction andreadily commercially available. One type of such quick-disconnectcoupling which is readily adaptable to the practice of the presentinvention is available from the Hanson Manufacturing Company, ofCleveland, Ohio.

Operation of the basic connector described above is accomplished in aconventional manner, that is, the release of the plug 12 from the socket10 is impossible until the sliding sleeve valve 32 is moved to the left(as shown in FIG. 2) to thereby move the passageway formed by radialgroove 34 into a non-communicating position with respect to the orifices30 on either side of the barrier 28. This shuts off the flow of fluidthrough the coupling. Downstream fluid under pressure exhausts axiallyalong the sides of the coupling, reducing the pressure in the forwardsection to zero. The locking mechanism sleeve 26 can then be movedaxially (to the left) along the length of the body to the position shownin FIG. 2, to release the locking balls 22 and thereby allow the plug tobe withdrawn.

The present invention resides in the provision of, and the adaptation ofa conventional connector plug and socket as above described into, aquick disconnect coaxial coupling arrangement for connecting coaxialfluid lines. Coaxial fluid lines generally include a first outer lineinto which a second, smaller diameter, line is coaxially arranged suchthat two separate fluids may be transported in the space of a singleline.

The second or inner coaxial cooperating plug 14 and second or innersocket 16 provided in accordance with this invention are bestillustrated in FIGS. 3 and 4, wherein detail portions of thepreviouslydescribed conventional outer connector have been omitted forclarity. The inner plug 14 is basically an elongated, rigid, hollowmetal tube. One end 39 of the tube may be provided with a tapered andcircumferentially ridged engaging portion for insertion into the innercoaxial fluid line. The opposite or leading end of the plug 14 isprovided with a rounded end portion 40. A circumferential groove isprovided in the outer diameter a slight distance back from the leadingend portion 40, into which an O-ring 42 is positioned for sealingengagement with an inner diameter 44 of the second or inner socket 16,which is fixed centrally of the first or outer plug 12.

The inner plug 14 is fixed within the wall or barrier 28 and extendscoaxially with the passageway 19. The plug 14 is sealed with respect tothe wall 28 by means of an O-ring 46 positioned in a circumferentialgroove 48 in the plug 14. Snap rings 50 positioned in correspondinggrooves in the plug 14 on opposite sides of the wall 28 hold the plugand prevent its axial movement. A limited amount of radial or pivotaltravel is allowed, however, to assist in alignment with the inner socket16 when the connector is coupled. Plug 14 is free to rotate with respectto outer socket 10 to prevent wind-up of tubing attached to the plug 14during installation.

The second or inner socket 10 has a housing 52 with an axial bore alongits length. The housing 52 is machined to have a plurality of flat areas54 (FIG. 4) along the sides thereof, at least along those portionsdisposed within the plug 12. More particularly, in its preferred form,the outer configuration of such portions of the housing 52 is basicallytriangular in shape, having rounded corner portions 56 which correspondto the inner diameter of the passage 19a within outer plug 12. Therounded corners 56 fit within the inner diameter of the first plug 12,where the socket member 16 is secured, as by welding, brazing, or thelike. The spaces between the flat triangular side portions 54 and theinner diameter of the plug 12 then form a plurality of passageways 58(FIGS. 3 and 4) for the flow of the first fluid through the outer plug.

An axial bore 60 (FIG. 3) through the length of the second or innersocket 16 forms the passageway for a second fluid. The axial bore 60includes the enlarged diameter entrance portion 44 which receives therounded end 40 of the inner plug 14. The bore 60 also has a threadedportion in which a spring-loaded check valve 62 is positioned. Thisvalve may be of conventional construction as, for example, a tire valvecore, and includes a spring-loaded plunger and a seat to allow the flowof fluid under pressure in a first direction, i.e., from the inner plug14 through and out of the inner socket 16, and through the axial boreprovided through the various parts. The outlet end of the inner socket16 may be provided with a nipple 64 threadably received in the end ofthe bore 60. A washer (not specifically shown) may be positioned betweenthe hexagonal head flange on the nipple which abuts the end of thesocket, to prevent leakage of the fluid passing therethrough. Anextended end of the nipple may be provided with rib-like projections 68for engagement within continuing inner coaxial fluid line (not shown).

A modified valve construction for the inner coaxial socket isillustrated in FIG. 5. In this embodiment, like reference numeralsbearing the suffix letter a are utilized to describe like pats. Theinner plug 14a is provided with the rounded end portion 40a and an Oring 42a is positioned in a groove about the outer diameter of the plug.The inner socket 16a is constructed similar to that described previouslyand is fixed within the inner diameter of the outer plug 12a as bywelding or the like to form a plurality of first fluid passageways 58a.The bore 60a, however, includes an area of reduced diameter 70 taperingoutwardly toward the exit end of the socket to form a valve seat 72. Aball valve 74 which may be constructed of nylon or similar material isadapted to seat on valve seat 72 and is biased into closed position by abias spring 76. The spring 76 is held in position within the bore 60aand against ball 74 by the nipple 64a threadably received in the bore60a in the same manner as previously described. The amount of pressurerequired to displace the ball 74 from the seat 72 may be varied bychanging the characteristics of the bias spring 76.

Referring again to FIGS. 1 through 4, in use the coaxial fluid lineswhich are to be attached are connected to opposite ends of theconnector, at the threaded portion 80 on the outer plug assembly 12 andat the ribbed portion 68 of the nipple on the inner socket 16 and at theopposite end of the connector at the internally threaded portion 82 onthe outer socket 10 and the ribbed end extremity 39 on the inner plug14. To connect the two main components of the coupling together, theouter plug 12 and inner socket 16 are pressed into the outer socket 10and inner plug 14, such that the locking balls 22 are ultimately biasedinto position within the groove 24 in the outer plug 12. It should benoted, however, that the forward rounded end 40 of the inner plug 14 isof such a length relative to the other parts of the coupling that thisend is inserted into the inner diameter bore opening 44 of the innersocket, the sealed relation, prior to the locking of the balls 22 withinthe groove 24, and thus prior to the movement of sleeve valve 32 intoposition allowing flow through the outer passage. This insures thatthere will be no leakage of fluid from the inner passage prior to timeflow is established or allowed through the outer passage. This can bequite important where, for example, air tools are lubricated through theinner passage and driven through the outer passage. When both passagesare thus connected, in the manner just described, two separate coaxialpassageways are formed through the length of the connector to allowsimultaneous, but independent, passage of two separate fluids.

In one practical application of the invention the inner passage formedthrough the second plug 14 and second socket 16 is utilized for thetransmission of oil or other liquid coolant or lubricant. The outerpassage formed through the bore of the body 18 through the ports 30 andin the passageways 58 formed between the second socket and first plug isutilized for the transmission of compressed air. The pressure at whichthe oil is transmitted is sufficient to overcome the bias of the checkvalve (62 as in FIG. 3, or 74 as in FIG. 5) to allow the passage of thefluid through the bore. Disconnection of the two coaxial line sectionsis readily accomplished in the same manner as for a conventionalsingle-passage coupling, i.e., by sliding the sleeve valve 32, and thenthe locking sleeve 26, to the left as viewed in FIG. 3, and removing theouter plug 12 from the outer socket 10. Simultaneously, the inner plug14 and inner socket 16 are disconnected from each other. The check valve62, (FIG. 3) or 74 (FIG. 5) then seats, to prevent the flow of the fluidfrom the inner line.

A modified embodiment of the invention is illustrated in FIG. 6, whereina slightly different basic style of quick disconnect socket member isutilized, but which like the previous such member has also been usedheretofore in single-tube lines. In this embodiment, the socket member81 is basically similar to that previously described, but includes acentrally located valve 90 for the outer socket to stop the flow of afirst fluid when the coupling is disconnected. The remaining details ofthe construction of the mechanisms for engaging the outer plug areessentially the same to that previously described and include aplurality of locking balls 83 spaced in recesses formed about thediameter of the socket body 88 for cooperative locking engagement with aperipheral groove 84 formed in the outer plug portion 85. A lockingsleeve 86 is slidably mounted along a portion of the body and is biasedforwardly (i.e., toward the plug 85) by coil spring 87, to move theballs 82 inwardly and into locking engagement with the groove 84 in theouter plug structure 85, in the position illustrated in FIG. 6.

The valve 90 includes two basic operating components, a seating surface92 having a central opening 94 therein, and a valve closure member 96.The closure member 96 is normally biased into engagement with the seat92 by bias spring 98 to close the central opening 94. An inner plug 100having essentially the same configuration as the inner plug member 14described in connection with FIGS. 1 - 5 is fixed centrally within andfor movement with the valve closure member 96, against the force of biasspring 98. An inner socket member 102 positioned within the outer plug85 is also similar to that previously described and illustrated in FIGS.1 through 4, or 5.

As the outer plug 85 and the inner socket 102 are placed into engagementwith the outer socket 80 and the inner plug 100, the inner plug 100 ismoved axially by the inner socket along the length of the assemblyovercoming the bias spring 98. This shifts the valve closure member 96away from the valve seat 92 and allows passage of the first fluidthrough the opening 94. The second fluid passageway through the innerplug and socket is the same as that previously described, and it is tobe observed that in this embodiment, like the one described previously,the forward end of the inner plug engages and seals within the innersocket before valve closure member 96 is pushed away from seat 92, toinsure that there will be no leakage from the inner passage before theconnection of the outer passage is established.

It will be recognized that various check valve arrangements andplacements may be utilized within the inner plug or socket portion ofthe invention to control the fluid flow through the center passage ineither direction. In one application of the invention for use withlubricators and like devices of the kind known as "Venturi type" in whchthere is positive pressure at the inlet or upstream end of the innerplug, the check valve associated with the inner plug and socket may bepositioned at the inlet end of the inner plug structure. Such aconstruction is illustrated in detail in FIG. 7. In this embodiment, aninner plug member 106 is mounted in a manner similar to that previouslydescribed in connection with FIGS. 1 through 6. In this embodiment,however, a differential check valve assembly 108 is provided at theinlet end of the inner plug member 106. An axial bore 110 through theplug is enlarged near the entrance opening to form a conical or likevalve seat 112. A ball valve 114 is positioned within an enlargeddiameter entrance opening adjacent the valve seat 112 and, when there issome pressure in the bore 110 between the coupling and the lubricator(as is normally the case) the ball valve 114 is biased out of seatingengagement by the combined effect of the pressure just noted plus theforce from a bias spring 118 positioned between the seat and the reduceddiameter bore 110. This is the condition shown in FIG. 7. The ball andsocket are retained within the end of the plug by a nipple 120threadably received in the end of the plug. In operation with alubricator or device of the type referred to, when pressures upstreamand downstream from the ball valve are within a predetermined range ofnear equality, the flow through passageway 110 is continuous sincespring 118 will maintain base 114 of seat 112 sufficiently to allowupstream pressure to overcome the bias spring force, as when thecoupling is disconnected, the ball seals off the opening until thedownstream pressure plus the spring force is approximately the same asthe upstream spring force, whereupon fluid flow is again allowed.

Conversely with a lubricator of the kind shown as "positive displacementtype" in which the upstream portion of the inner line is filled withfluid (but not under pressure), the check valve may take a form such asis shown in FIGS. 3, 4 or 6, wherein the valve seats to prevent flowthrough the center passage of the coupling when there is no reducedpressure or fluid displacement from the downstream end of the innersocket, e.g., on nipple 64 or 64a, i.e., when the coupling isdisconnected.

The present invention will therefore be seen to provide a simple,easily-fabricated coupling member for simultaneous "quick-disconnect"connection of each of a pair of coaxial fluid lines. While the couplingis relatively simple in construction, it is nonetheless very efficientin its operation. The assembly, as hereinabove described, may beaccomplished by a relatively simple modification of standard forms ofsingle-line connectors or it may be a complete assembly onto itself,specifically designed for a coaxial fluid application. While it is notstrictly necessary, for example, to incorporate a check valve within theplug and socket portions exactly in the same manner as specificallydescribed, it is contemplated that within the scope of this invention,the check valves, differential pressure valves and the like may beincorporated in either of the plugs or sockets to prevent fluid flowwhen disconnected. In addition, the inner plug and socket may becoaxially mounted within the outer plug and socket, respectively, ratherthan in the coaxial plug to socket and socket to plug relationshipillustrated.

While a preferred and several alternate embodiments of the inventionhave been illustrated and described, it will be recognized by thoseskilled in the art that other embodiments and modifications of theinvention incorporating the teachings hereof may be readily made in thelight of this disclosure. All modifications embodying the principles ofthis invention are therefore considered as included in the appendedclaims unless these claims by their language expressly state otherwise.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A coupling member formaking inline connections of the respective ends of both the inside andoutside conduits in "coaxial" type telescoped fluid lines, comprising:amutually engageable first plug member and said socket member each havingan end portion with means for attaching thereto the respective ends ofone of said fluid conduit lines at an interruption therein and having apassageway therethrough for passage of a first fluid; attachment meanson said plug and said first socket for releasably connecting sametogether when mutually engaged; a second plug member and a second socketmember positioned in telescoping relation with respect to said firstplug and said first socket member; said second plug and said secondsocket each having an end portion with means for attaching thereto therespective ends of a different one of said fluid conduit lines at aninterruption therein and having a passageway therethrough for passage ofa second fluid, said second plug and socket having portions whichcooperatively engage each other when said first plug and socket areconnected; means mounting portions, including at least the said endportions, of at least one of said first or second plug or socket membersso as to be angularly movable about the longitudinal axis of thecorresponding part of the coupling which is in telescoping relation withsuch plug or socket members; and valve means in at least one of saidfirst and said second plug and said first and said second socket tocontrol flow of fluid in at least one of said first and said secondpassageways.
 2. The apparatus as defined in claim 1 wherein said secondsocket is mounted within said first plug and said second plug is mountedwithin said first socket.
 3. The apparatus as defined in claim 1 whereinsaid valve means is positioned in said first socket, said valve meansincluding:a gate member positioned in said first passageway of saidfirst socket; fluid bypass means communicating across said gate means;and sleeve valve means slidably mounted on said socket member andshiftable to allow or to shut off fluid flow through said fluid bypassmeans.
 4. The apparatus as defined in claim 3 wherein said gate means ispositioned transversely of said first passageway in said first socketmember, and said second plug member is mounted in said gate means andgenerally coaxially with said first passageway.
 5. The apparatus asdefined in claim 1 wherein said valve means is carried by said firstsocket.
 6. The apparatus as defined in claim 5 wherein said valve meansis carried by said second socket.
 7. The apparatus as defined in claim 5wherein said valve means is carried by said first socket and said secondplug.
 8. A coupling member for making in line connections of therespective ends of both the inside and outside conduits in coaxial typetelescoped fluid lines, comprising:a generally tubular cross socket, anda plug joinable with said socket member by insertion, both such membershaving an outwardly disposed end portion with means for attachingrespective ends of the outer one of said fluid conduit lines thereto,and both defining inner passages therethrough which are in fluid flowcommunication when said members are joined; a transverse interior wallwithin said outer socket member intersecting the passage therethrough,and fluid flow passage means for conducting fluid past said wall; anelongated tube member mounted within said outer socket and passingthrough said transverse wall, said tube member having a hollow interiorforming a fluid flow passage inside said socket, and having an outwardlydisposed first end portion with means for attaching an end of the innerone of said fluid conduit lines thereto and a projecting second endportion; a mating member for interfitting with and connection to saidelongated tube member when said outer socket and plug are joined, saidmating member carried within said outer plug and having an open end forengaging said projecting second end portion of said elongated tubemember, said mating member further having an interior passagecommunicating with that of said elongated tube member through said openend and extending to an opposite end portion of said mating memberhaving means for attaching the other end of said inner one of said fluidconduit lines thereto; means mounting portions, including at least thefirst end portion which attaches to said inner fluid conduit line, of atleast said elongated tube member or said mating member for continuousrotation relative to the outer socket or plug which is outside such tubeor mating member even when said tube member and mating member areinterfitted together and connected, to prevent wind-up or twisting ofthe fluid conduit line attached to such end portion; and valve means forcontrolling fluid flow through at least one of said inner fluid flowpassages of said outer socket and plug and said elongated tube memberand its said mating member.
 9. The coupling member as defined in claim 8wherein said transverse wall defines an opening therethrough and saidelongated tube member extends through such opening.
 10. The couplingmember as defined in claim 9, wherein said tube is mounted in said outersocket for at least limited movement within said opening and relative tosaid wall.
 11. The coupling member as defined in claim 10, wherein saidtube is mounted for longitudinal movement within said opening, andincluding valve means positioned for actuation by said tube during suchlongitudinal movement.
 12. The coupling member as defined in claim 11,wherein at least part of said valve means is carried by said tube duringits longitudinal movement.
 13. The coupling member as defined in claim12, and including a cooperative part of said valve means mounted on saidtransverse wall for cooperation with said part carried by said tube. 14.The coupling member as defined in claim 13, wherein said outer socketand plug comprises a "quick-disconnect" coupling pair of the type havinginterlocking means for holding the two together when so joined and anexternally-accessible release element for effecting substantiallyinstantaneous release of said interlocking means to thereby provide forseparation of the coupling pair.
 15. The coupling member as defined inclaim 8, wherein said mating member comprises a structure disposedinside said outwardly disposed end portion of said outer plug, saidstructure defining at least in part an internal passage forcommunicating with that of said elongated tube and also defining atleast in part recesses which are in flow communication with the saidinner passages of said outer plug.
 16. The coupling member as defined inclaim 15, including valve means located at least in part within saidinternal passage of said mating member structure.